Abstract: A process is described for the formation of an undercoat which is in turn useful in forming a CRT metal back layer. According to the process, a pretreatment composition is coated on a glass panel having a fluorescent layer overlaid thereon, so that a water film is formed. The pretreatment composition is composed of 2-20 wt. % of an alkyl monoalcohol having a C.sub.1-3 alkyl group, 0.05-1 wt. % of a water-soluble, high molecular compound and 79-97.95 wt. % of water. An undercoating composition is then coated on the water film by a wet-on-wet coating method, whereby a coating layer is formed. The undercoating composition is composed of 1-7 parts by weight of an acrylic resin, which has been obtained by polymerizing 90-100 wt. % of an alkyl methacrylate having a C.sub.1-4 alkyl group other than tertbutyl methacrylate and 0-10 wt. % of an ethylenically unsaturated monomer copolymerizable therewith, and 99-93 parts by weight of a solvent containing at least 80 wt. % of toluene.

Abstract: The invention provides an end structure for at least one optical fiber ribbon wherein the same-side ends of the optical fiber ribbons are bundled together and tightly fitted in a metallic sleeve member so that coating layers of the optical fiber ribbons may be on the inner surface of the metallic sleeve member.

Abstract: The invention provides a working equipment for roughening the side of optical fiber having a hot stamper, a sheet having rough surface to be transferred, a cushion, and a cushion-mounted plate having a portion formed in stepwise or continuously curved or sloped form.

Abstract: An optical fiber device comprises a core and a cladding, the core being made of an optical material having a refractive index n.sub.1, and the cladding being made of an optical material having a refractive index n.sub.2, the end of the optical fiber from which light radiates forming a plane that is inclined to the fiber axis by an angle .theta., a light reflective layer being formed at least on the outer periphery of said radiating end, and the two reractive indices n.sub.1 and n.sub.2 satisfying the following relation (1):n.sub.1 -n.sub.2 .gtoreq.0.01 (1).

Abstract: A method for the fabrication of an optical fiber sheet, which comprises supplying a number of optical fibers, arranging them in a plane so that they do not intersect one another, holding the optical fibers by a tool having a clearance slightly larger than the size of the fibers, constringing the fibers in the held portion in the lateral direction to bring them close to one another so that the fibers are contacted with one another, and applying an adhesive to the contacted portion of the fibers and solidifying the adhesive to fix the fibers in the sheet-like form, an apparatus for carrying out the method and an optical fiber sheet prepared according to the method.

Abstract: A slub yarn, in which a sheath component is wound around a core component to form a plurality of slub portions along the axis of the yarn, which structure is obtained by simultaneously false-twist texturing the core and sheath components. The slub yarn has a feature that the slub portion includes a multilayered winding structure of seven or more layers of the sheath component wound around the core component. A method for producing the slub yarn includes a step of overfeeding a sheath component to a core component in the direction substantially perpendicular to a passage of the core component in a twisting zone of a false-twist texturing machine while the sheath component is guided by a guide repeatedly traversed along a passage of the core component, a distance between the guide and the passage of the core component being kept in a range not shorter than 10 cm. An apparatus for randomly traversing the sheath component along the core component during the false-twist texturing process is also provided.